Masashi Ueno

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Background. Cancer patients are at high risk of developing a second cancer after the treatment of initial cancers. Understanding the characteristics of multiple primary cancer is important to establish an effective surveillance program for the early detection of second cancers. Methods. We analyzed the cancer registry records from 1986 to 1995 at the Cancer(More)
BACKGROUND Although the laparoscopic approach is accepted for the treatment of colon cancer, its value for low rectal cancer is unknown. The purpose of this study was to evaluate the influence of patient and tumor factors, particularly pelvic dimensions, on the difficulties in laparoscopic total mesorectal excision (TME) for low rectal cancer. METHODS(More)
BACKGROUND Laparoscopic rectal cancer surgery involving rectal division with intracorporeal stapling devices is technically difficult. This study aimed to identify risk factors for anastomotic leakage associated with laparoscopic anterior resection for rectal cancer. METHODS We studied 363 patients who underwent laparoscopic anterior resection with(More)
The role of laparoscopic surgery for transverse colon cancer (TCC) remains controversial. This study aimed to evaluate the safety of laparoscopic resection of TCC. Fifty-three patients undergoing laparoscopic resection of TCC (group A) were compared with 39 patients undergoing open resection of TCC (group B) and 200 patients undergoing laparoscopic(More)
The present study aims to define the prognostic impact of the lymph node ratio (LNR) in patients with stage III distal rectal cancer. We analyzed data from 501 patients who underwent curative resection (total mesorectal excision, TME) for stage III distal rectal cancer at 12 institutions between 1991 and 1998. Patients were divided into four groups(More)
PURPOSE Colorectal cancer and gastric cancer are the two most commonly associated malignancies in Japan. We examined mismatch repair deficiency in the tumors of patients with primary colorectal and gastric cancers retrospectively. METHODS In 103 cases and 102 healthy control subjects, surgical specimens of colorectal and gastric cancer underwent(More)
Laparoscopic resection for colorectal cancer is increasingly being performed worldwide. Although learning standardized procedures under the supervision of an experienced surgeon may be effective, there is currently no information on the learning curve under such circumstances. This single-center study aimed to evaluate the learning curve for laparoscopic(More)
Background: The efficacy of thoracoscopic radical esophagectomy for cancer has yet to be established, mainly because previous reports have not included a sufficient number of cases. Methods: Seventy-five treatment-naive patients with esophageal cancer without contiguous spread underwent esophageal mobilization and extensive mediastinal lymphadenectomy(More)
The incidence of aberrant bile duct injury associated with laparoscopic cholecystectomy (LC) has not yet been adequately examined. This study aimed to clarify the types of normal cystic ducts and the incidence of aberrant extrahepatic bile ducts, and to search for a method of avoiding injuries during LC. Aberrant hepatic ducts were retrospectively(More)
BACKGROUND AND AIM A treatment strategy for tumors with only venous invasion and characteristics of small rectal carcinoids with metastasis have not been clearly documented. The present study aims to determine the risk factors for lymph node metastasis and to elucidate characteristics of small tumors with metastasis. METHODS We investigated a total of 229(More)